ADELAIDE, capital of South Australia, in the county to which it gives its name, is situated near the middle of the east ern side of St. Vincent gulf where the coast line curves farthest inland (eastwards). The genius of Sturt, and then of Light, the first surveyor-general, selected (1836) a site upon fertile plains which here sweep up very gently from the coast to a curving line of hills some 9m. inland. (Mt. Lofty, c. 7m. [air-line] E.S.E. of Adelaide, 2,334 feet.) Light chose, not without opposition, a spot on rising ground, close to the Torrens stream, the chief early source of water-supply, and within easy reach of a fair open roadstead (Holdfast bay, c. 6m.). Within 8m. also was the only considerable sheltered inlet along this recently elevated coast, the Port Adelaide "river," a deflected tidal estuary. This water—shallow, muddy, but improved by dredging—became the site of Adelaide's port until the construction of the outer harbour provided a more accessible anchorage for larger vessels near the mouth of the estuary and facing the open gulf. South wards the hills close in upon the plain and meet the coast line, but northwards the lowlands stretch, broadening, up to and be yond the head of the gulf. Easy movement was possible also by various gaps and saddles to the Murray lowlands in the east and south-east, and Adelaide thus soon became an important nodal point for lines of movement by land and sea. The fertility of the plains—deep alluvium washed down from the torrent-scarred hills—the presence of minerals (though in relatively small quanti ties) in the hills, and the genial climate formed the basis of Adelaide's prosperity. A fairly regular rainfall of c. 21 in. falling largely in the winter months (April–November) ; temperatures hot in summer (Jan. mean : 73° ; highest recorded [shade] maximum 116°, with fairly frequent heat spells) ; but cool and bracing in winter (June mean: 52° with occasional frosts) ; land and sea breezes along the coast and much sunshine make up a typical Mediterranean climate.
The town was laid out by Light in the form of a square, di vided into rectangular blocks with gardens and parks at the points of intersection. Around the square a mile-broad belt of park-land was reserved, and beyond these stretch the suburbs. The park-lands have been to some extent encroached upon for public buildings, but the remainder form the great playground and "lungs" of the city which claims to have no slums. The climate and the presence of the river Torrens, now artificially dammed and converted into a lake, lend Adelaide the peculiar charm of diversified vegetation ; north-western European, south ern European and sub-tropical.
After a somewhat chequered early history Adelaide, in virtue of its commanding situation in relation to all the more important southern parts of the State, steadily grew in prosperity and size until, with 312,629 inhabitants, it had a decidedly alarming proportion (nearly 54%) of the total population of the State (1933), 580,987. Its commercially central position and good communications, ready supplies of raw materials and of imported coal, and a protective tariff have built up in the metropolitan area (particularly along the main lines to Port Adelaide) a num ber of flourishing young industries, manufacturing woollens, ma chinery, pottery, etc. To Adelaide gravitate the products of the agrictiltural and pastoral areas of the surrounding fertile districts, and thither also, for lack of a river-mouth port, come the bulk of the products—wool, wheat, fruit—of the lower Murray valley (see ALEXANDRINA, LAKE). The trade of Port Adelaide (1924-25: 125.9 million; 2,074 million tons) is five to six times as valuable as that of any other South Australian port, and fourth as regards value and tonnage amongst the ports of Australia.
The city possesses many fine buildings, including the University, School of Mines, an Anglican and a Roman Catholic Cathedral, Exhibition Building and others. It was the birth place of municipal government in Australia and gained a Lord Mayoralty in 1919.